// JavaScript Document
jQuery.extend({
    createUploadIframe: function(id, uri){
    	//create frame
        var frameId = 'jUploadFrame' + id;
        
        if(window.ActiveXObject) {
            var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
            if(typeof uri== 'boolean'){
                io.src = 'javascript:false';
            }
            else if(typeof uri== 'string'){
                io.src = uri;
            }
        }
        else {
            var io = document.createElement('iframe');
            io.id = frameId;
            io.name = frameId;
        }
        io.style.position = 'absolute';
        io.style.top = '-1000px';
        io.style.left = '-1000px';

        document.body.appendChild(io);

        return io;   
    },
    createUploadForm: function(id, fileElementId, data){
    	//create form 
    	var formId = 'jUploadForm' + id;
    	var fileId = 'jUploadFile' + id;
    	var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>'); 
    	var oldElement = jQuery('#' + fileElementId);
    	var newElement = jQuery(oldElement).clone();
    	jQuery(oldElement).attr('id', fileId);
    	jQuery(oldElement).before(newElement);
    	jQuery(oldElement).appendTo(form);
    	//set attributes
    	jQuery(form).css('position', 'absolute');
    	jQuery(form).css('top', '-1200px');
    	jQuery(form).css('left', '-1200px');
    	jQuery(form).appendTo('body');  
    	
    	if (data) {  
    		for (var i in data) {  
		        $('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);  
		    }  
		}
    	
    	return form;
    },

    ajaxFileUpload: function(s) {
        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout  
        s = jQuery.extend({}, jQuery.ajaxSettings, s);
        var id = s.fileElementId;        
        var form = jQuery.createUploadForm(id, s.fileElementId, s.data);
        var io = jQuery.createUploadIframe(id, s.secureuri);
        var frameId = 'jUploadFrame' + id;
        var formId = 'jUploadForm' + id;  
        
        if( s.global && ! jQuery.active++ ){
        	// Watch for a new set of requests
        	jQuery.event.trigger( "ajaxStart" );
        }            
        var requestDone = false;
        // Create the request object
        var xml = {};   
        if( s.global ){
        	jQuery.event.trigger("ajaxSend", [xml, s]);
        }            
        
        var uploadCallback = function(isTimeout){  
        	// Wait for a response to come back 
        	var io = document.getElementById(frameId);
            try{    
            	if(io.contentWindow) {
            		xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
            		xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
            	}else if(io.contentDocument){
            		xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
            		xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
            	}      
            }catch(e){
            	jQuery.handleError(s, xml, null, e);
            }
            if( xml || isTimeout == "timeout")  {    
                requestDone = true;
                var status;
                try {
                    status = isTimeout != "timeout" ? "success" : "error";
                    // Make sure that the request was successful or not modified
                    if( status != "error" ){
                        // process the data (runs the xml through httpData regardless of callback)
                        var data = jQuery.uploadHttpData( xml, s.dataType );                        
                        if( s.success ){
                        	// ifa local callback was specified, fire it and pass it the data
                        	s.success( data, status );
                        };                 
                        if( s.global ) {
                        	// Fire the global callback
                        	jQuery.event.trigger( "ajaxSuccess", [xml, s] );
                        };                            
                    } else {
                    	jQuery.handleError(s, xml, status);
                    }
                } catch(e)  {
                    status = "error";
                    jQuery.handleError(s, xml, status, e);
                };                
                if( s.global ){
                	// The request was completed
                	jQuery.event.trigger( "ajaxComplete", [xml, s] );
                };
                    

                // Handle the global AJAX counter
                if(s.global && ! --jQuery.active){
                	jQuery.event.trigger("ajaxStop");
                };
                if(s.complete){
                	s.complete(xml, status);
                } ;                 

                jQuery(io).unbind();

                setTimeout(function(){ 
                	try  {
                		jQuery(io).remove();
                		jQuery(form).remove(); 
                	} catch(e) {
                		jQuery.handleError(s, xml, null, e);
                	}         
                }, 100);
                
                xml = null;
            };
        };
        // Timeout checker
        if( s.timeout > 0 ) {
            setTimeout(function(){
                if( !requestDone ) {
                	// Check to see if the request is still happening
                	uploadCallback( "timeout" );
                }
            }, s.timeout);
        }
        try  {
        	var form = jQuery('#' + formId);
        	jQuery(form).attr('action', s.url);
        	jQuery(form).attr('method', 'POST');
        	jQuery(form).attr('target', frameId);
            if(form.encoding){
                form.encoding = 'multipart/form-data';    
            }
            else{    
                form.enctype = 'multipart/form-data';
            }   
            jQuery(form).submit();

        } catch(e){   
            jQuery.handleError(s, xml, null, e);
        }
        if(window.attachEvent){
            document.getElementById(frameId).attachEvent('onload', uploadCallback);
        }
        else{
            document.getElementById(frameId).addEventListener('load', uploadCallback, false);
        }   
        return {abort: function () {}}; 

    },

    uploadHttpData: function( r, type ) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        // if the type is "script", eval it in global context
        if( type == "script" ){
         jQuery.globalEval( data );
        }
            
        // Get the JavaScript object, ifJSON is used.
        if( type == "json" ){
         eval( "data = " + data );
        }
            
        // evaluate scripts within html
        if( type == "html" ) {
         jQuery("<div>").html(data).evalScripts();
        }
            
        return data;
    }
});
